Desenvolvimento de um novo sistema Multiplex de microssatélites (STR) para análise genética de populações humanas

Abstract

The present work presents the development of a new system called multiplex Pentaplex-ised, composed of 5 microsatellite loci STR type (D5S198498, D3S18773, GH15, D8S82535 and D11S118590). Such microsatellites have been identified in the human genome, using the program BLAST-N (GenBank). Specific primers were designed for amplification via PCR. Fluorescent primers were synthesized to allow simultaneous analysis of multiple amplicons (multiplex analysis). All microsatellite loci were genotyped confirming the high degree of polymorphism. In the validation, the minimum DNA concentration of for amplification was estimated at 0.25 ng. Several types of biological samples (blood, saliva, urine and semen) were acquired satisfactorily. We built a database of microsatellite allele frequencies for three Brazilian populations -Amazonas, Rio de Janeiro and Espírito Santo. The distributions of allele frequencies showed little variation between population groups. By means of statistical tests of χ2 using the program Arlequim 3.1 most alleles do not adhere to Hardy-Weinberg equilibrium if performed separately for each of the populations. However, in the analysis performed with the whole set of three populations, there is high adherence to the Hardy-Weinberg equilibrium. The three populations were grouped and compared pair-to-pair, showing that the genetic variation is greater within populations than between them. Statistical data about the power of exclusion, discrimination power and polymorphism information content for the five loci were determined for each STR and together to assess the potential of the system Pentaplex-ised in human identification. We observed that this multiplex system is suitable for human identification and that can be used in a complementary method with other systems for genetic analysis, by having a cumulative power of discrimination of 99.996% and 93.436% cumulative exclusion